Method for the isolation of nucleic acids

Abstract

The present invention concerns an improved method for the isolation of nucleic acids such as DNA and RNA from bacterial, plant, animal or human cells as well as from cell cultures and virus cultures, wherein the nucleic acid is immobilised on a matrix having a silicon-oxygen compound in the presence of a chaotropic agent and an alkanol, carried out in a temperature range of 36° to 75° C.

The invention claimed is: 
     
       1. In a method for the isolation and/or purification of a nucleic acid comprising:
 a) lysis of a biological sample, 
 b) immobilization of a released nucleic acid on a matrix having one or more silicon-oxygen compounds in the presence of a chaotropic compound and a branched or linear alkanol, 
 (c) separation of the bound nucleic acid from said sample, and wherein and optionally washing the nucleic acid immobilized on the matrix following step (b) 
 the improvement comprises immobilization of the nucleic acid at a temperature range of 46° C. to 75° C. 
 
     
     
       2. The method according to  claim 1 , wherein the immobilization is carried out at a temperature in the range of 50° C. to 65° C. 
     
     
       3. The method according to  claim 2 , wherein the immobilization is carried out at a temperature of 56° C. 
     
     
       4. The method according to  claim 1 , wherein the silicon-oxygen compound comprises silica. 
     
     
       5. The method according to  claim 1 , wherein the matrix is represented by magnetic particles having a silica surface. 
     
     
       6. The method according to  claim 1 , wherein the chaotropic compound comprises a chaotropic sodium or guanidinium salt. 
     
     
       7. The method according to  claim 6 , wherein the chaotropic sodium or guanidinium salt is sodium iodide, sodium perchlorate, guanidinium thiocyanate, guanidinium isothiocyanate or guanidinium hydrochloride or a mixture thereof. 
     
     
       8. The method according to  claim 1 , wherein the branched or linear alkanol comprises an alcohol with one to five carbon atoms. 
     
     
       9. The method according to  claim 8 , wherein the alcohol comprises methanol, ethanol, isopropanol or a branched or linear butanol or pentanol or a mixture thereof. 
     
     
       10. The method according to  claim 8  wherein the alkanol is present in the form of an aqueous solution in a concentration from 1 to 100% volume/volume. 
     
     
       11. The method accordign to  claim 1 , comrpising after step (b):
 washing the nucleic acid immobilized on the matrix. 
 
     
     
       12. The method of  claim 11 , wherein said biological sample is selected from the group consisting of body fluid, blood, plasma, urine, a tissue sample, and cells. 
     
     
       13. The method of  claim 11 , wherein said biological sample comprises viruses, phages, and/or cells. 
     
     
       14. The method of  claim 1 , wherein said biological sample is selected from the group consisting of body fluid, blood, plasma, urine, a tissue sample, and cells. 
     
     
       15. The method of  claim 1 , wherein the isolation and/or purification yield of a nucleic acid is increased when immobilization of the nucleic acid is carried out at a temperature range of 46° C. to 75° C. as compared to when immobilization of the nucleic acid is carried out at a temperature of 26° C. 
     
     
       16. The method of  claim 1  comprising:
 a) lysis of a biological sample, wherein said biological sample is selected from the group consisting of body fluid, blood, plasma, urine, a tissue sample, and cells; 
 b) immobilization of a released nucleic acid on a matrix having one or more silicon-oxygen compounds comprising silica in the presence of a chaotropic compound, wherein the chaotropic compound comprises a chaotropic sodium or guanidinium salt, and a branched or linear alkanol, wherein the branched or linear alkanol comprises an alcohol with one to five carbon atoms, and optionally washing the nucleic acid immobilized on the matrix, 
 (c) separation of the bound nucleic acid from said sample, wherein immobilization of the nucleic acid is carried out at a temperature range of 46° C. to 75° C. 
 
     
     
       17. The method of  claim 1 , wherein said biological sample comprises viruses, phages, and/or cells. 
     
     
       18. In a method for the immobilization of a nucleic acid on a matrix having a silicon-oxygen compound in the presence of a chaotropic agent and a branched or linear alkanol, the improvement comprising immobilization of the nucleic acid is carried out in a temperature range of 46° to 75° C. 
     
     
       19. The method according to  claim 18 , wherein the immobilization on a matrix with a silica surface is carried out in the presence of a branched or linear alkanol of one to five carbon atoms or an aqueous solution thereof at a temperature in a range of 46° C. to 75° C. 
     
     
       20. The method according to  claim 19 , wherein the immobilization is carried out in the presence of methanol, ethanol, propanol, isopropanol, and/or a branched or linear butanol or pentanol or in the presence of an aqueous solution of an alcohol or a mixture thereof at a temperature in a range of 50° C. to 65° C. 
     
     
       21. The method according to  claim 20 , wherein the immobilization is carried out in the presence of an aqueous solution of methanol, ethanol, propanol and/or isopropanol in a concentration range of from 1 to 100% volume/volume at a temperature of 56° C. 
     
     
       22. The method according to  claim 18 , wherein the chaotropic compound is embodied by a chaotropic sodium or guanidinium salt. 
     
     
       23. The method according to  claim 22 , wherein the chaotropic sodium or guanidinum salt is at least one of sodium iodide, sodium perchlorate, guanidinium thiocyanate, guanidinum isothiocyanate or guanidinium hydrochloride. 
     
     
       24. The method according to  claim 18 , wherein the immobilization is carried out at a temperature in a range of 50° C. to 65° C. 
     
     
       25. The method according to  claim 24 , wherein the immobilization is carried out a temperature of 56° C. 
     
     
       26. The method according to  claim 18 , wherein the matrix is represented by magnetic particles with a silica surface. 
     
     
       27. The method of  claim 18 , further comprising washing the nucleic acid immobilized on the matrix.